1. Field of the Invention
The present invention relates to a cold work steel article. More precisely, the present invention relates to a cold work steel article with an improved property profile, in particular, with high strength and high ductility.
2. Discussion of Background Information
For a cold massive forming, e.g., with extrusion molding dies and dies for producing components and also for cutting tools with additional high demands regarding the toughness of the material, such as tap drills and the like, articles having an overall high property level of the material are required in modern technology. This is also caused by the expenditure entailed by tool production, because a complicated geometry of a component to be manufactured usually translates into high costs for the production of the corresponding tool.
This requirement should be seen primarily in terms of an improved economic efficiency in a large-scale production of parts or components. In order to keep the overall costs low, a material for the part for the respective use should be selected which due to the material properties, allows to obtain the longest possible service life of the part.
To improve the service life of a cold work steel article which is subjected to overall high stress during the use thereof, the material should have a high ductility to prevent tool breakages, and a high strength to ensure an accuracy with respect to size. Also, wear should be minimized.
Iron-based materials with a high carbide content, in particular, with a high monocarbide content in a hard matrix, exhibit increased resistance to abrasive wear. Such steels usually have a high carbon content of up to 2.5% by weight and a concentration of monocarbide-forming elements of up to 15% by weight, i.e., a high primary carbide content. However, they exhibit a low toughness in a heat-treated state. The microstructure, in particular, the carbide size and the carbide distribution in the material of the article can be improved by a powder metallurgical production, but in many cases the required toughness of the material can still not be achieved.
Improved toughness properties can be achieved with typical highly alloyed high-speed steel materials, e.g., those according to DIN (German Industrial Standard) material no. 1.3351, with powder metallurgical production of the parts, but this increase in the toughness of the material is not sufficient for particularly stressed articles, so that in long-term operation a breakdown often occurs by breakage of the same.
It would be desirable to have available a cold work steel article whose material exhibits increased toughness and compressive strength, high wear-resistance and hardness, and an improved fatigue resistance. In other words, it would be desirable to provide a cold work steel article with both high strength and ductility, which article, in particular in the form of matrices and dies, offers a high economic efficiency in a large-scale production of parts.